The present invention generally relates to combine harvesters.
More particularly, it relates to a combine harvester which has a mowing table, an inclined feed conveyor which transports the mowed product, a tangential or axial threshing mechanism located after the inclined feed conveyor, and finally two separating devices which are located after the threshing mechanism in a product flow direction, operate in accordance with the principle of an axial flow, and are each enclosed by a housing.
Each of the separating devices is provided with a chopper device which is arranged in the rear region facing away from the threshing mechanism. Its chopping knives pivotable between an operative position and an inoperative position are fixedly mounted at a distance from one another on supporting axles which are axis-parallel to the rotary axes of the separating rotors of the separating device.
In the combine harvester of the above mentioned type the inclined conveyor is followed by a threshing drum which operates in accordance with the principle of an axial flow or radial flow, and also a transfer drum. The separating rotors of the separating device located after it, depending on the construction of the combine harvester, can extend either parallel and at a distance from the wheel axles or transversely to them. The rotary axes of the separating rotors are parallel to one another and are located at a distance from one another. They extend either horizontally or enclose a small acute angle with the horizontal plane. The rear ends which face away from the threshing drum are higher than the front ends. In other words, the separating rotors rise in a threshed product flow direction. Each separating rotor is surrounded by a two-part housing, with an upper part forming a hood and a lower part forming a separating basket. In a predetermined region in the rear part of each separating rotor, its transporting elements are designed so that they can cooperate with the chopping knives arranged in series, when they are turned to the operative position. For this purpose, the chopping knives are fixedly mounted on the supporting axles which are axis-parallel to the associated separating rotors. When the straw must not be chopped, they are turned outwardly beyond the passage of the transporting elements to an inoperative position.
In the region of the chopper device, the lower part of the housing is formed as a trough. It is provided with a plurality of throughgoing slots for the chopping knives. The chopper device is provided with means for securing against foreign bodies, since it is not completely excluded that non-comminutable foreign bodies can be contained in the straw. The chopping knives are pressed by springs to the operative or working position. They can deviate when a foreign body is located in the straw. Since the chopper device is used selectively and the driver of a combine harvesters always operates under time pressure, it is desired that the operation be very simple and the stoppage times be as little as possible.